A laminate comprising at least one elastic film, particularly with an elastomer base, particularly thermoplastic, and at least one ply of non-woven material secured to the elastic film, is used in particular in applications in the field of clothing, in particular throwaway, such as training pants or devices for adult incontinence, or in the medical field in the form of elastic bandages. In the field of training pants, these laminates are conventionally used in the sections forming the waistband around the waist of the baby. In particular these laminates are used to realise the elastic tabs ensuring that the nappy is kept on the baby and supporting, amongst other things, a hook and loop fastener. In general the securing of the nappy or sheet of non-woven material to the elastic film is realised through the interposition of a bonding material, particularly glue, either continuously between the non-woven material and the elastic or in discrete zones, in particular in points or in lines. The securing of the non-woven material and the elastic film means that it is necessary to impart elasticity to the laminate by stretching it. This is an operation traditionally called “activation” in the field of training pants. In fact, before the laminate has been stretched it does not really have any elasticity or at least in the case of using non-woven fabric having a slight elasticity, it only has a slight elasticity compared to non-woven fabric. After activation, that is to say after the stretching of the laminate in its entirety, the laminate will have, by reason of a sort of breaking or coming-apart or de-cohesion of the fibres of the non-woven fabric, an elasticity which will correspond to that of the elastic film, of which the elastic capacities will thus have been released.
In order to realise this activation, it is known that the laminate can be passed in the form of a web or composite between two toothed rolls, of which the teeth engage in each other. The teeth of the rolls extend essentially perpendicularly to the direction of unrolling of the web (machine direction). The mutual engagement of the teeth while the laminate is between the two sets of toothing brings about the stretching of the laminate. Upon leaving the two rolls, the laminate assumes essentially the form which it had prior to entering the rolls. However, the distortion which takes place means that, now, the laminate as a whole has elasticity, namely a transverse elasticity between its initial width and its final width (in the non-stretched state) and the maximum width which it has when it is between the two toothed rolls. The laminate has thus been activated.
It is already known from the prior art and in particular the U.S. Pat. No. 5,167,897 that an activation of this kind can be realised. The web is unrolled therein with a virtually zero longitudinal tension and the outer peripheral edges of the laminate adjacent to the region to be activated are maintained, for example by depression or belt systems, during the action of the toothed rolls. The device used in its entirety is quite complicated, requiring in particular complex systems for maintaining the outer peripheral edges adjacent to the region of the laminate to be activated. Besides, the laminate obtained by these methods of the prior art presents risks of delamination or becoming unstuck at the outer edge of the laminate between the non-woven material and the elastomer in such a way that it is necessary to provide either glues with a strong sticking power or a solder line, particularly ultrasonic, along these edges.